“…Whitlock defined molecular complexity in terms of size (more bonds equate to greater complexity) and structural features such as rings, stereocenters, unsaturations, and heteroatoms . We have been engaged in a program in which reactions based on the interaction of allylic and benzylic alcohols with Re 2 O 7 and related species are employed to increase molecular complexity. , We reported a process (Scheme ) in which allylic alcohol transposition is followed by addition into a carbonyl group to form a cyclic hemiacetal or hemiketal, ionization to form an oxocarbenium ion, and bimolecular nucleophilic addition. , The process couples two fragments while creating a ring and at least one stereocenter, and the reversibility of the initial steps of the process allows for relative stereocontrol.…”